The objective of this project is to study the mechanism of carcinogenesis using quantitative two-dimensional gel electrophoresis (2DG). This technique lets us examine both qualitative and quantitative changes in the synthesis of thousands of cellular polypeptides as the cell undergoes neoplastic transformation. Research is focused on (1) the continued development of the computer system (dubbed ELSIE) to analyze gels and (2) the use of ELSIE to analyze experiments requiring computerized analysis of 2DGs. The ELSIE system is being used in the laboratory to study the effects of different transforming oncogenes on the synthesis of proteins. Rat liver epithelial (RLE) cells have been isolated and single-cell cloned. These cells have a normal diploid karyotype and represent a homogeneous, clonal system for the study of transformation. Different retrovirus containing transforming oncogenes, such as v-H-ras, v-N-ras, v-raf, or a v-myc/v-raf chimera have been used to transform RLE cells or a human diploid fibroblast line (LG-1). The polypeptide patterns of the transformed cells differ significantly from their non-transformed progenitors. While qualitative differences are rare, over 30% of the spots may vary quantitatively. Very similar oncogenes, such as v-H-ras and v-N-ras, cause essentially indistinguishable 2DG patterns. These patterns are distinct from those caused by v-raf and v-myc/v-raf mediated transformation. The v-raf and v-myc/v-raf patterns are also readily distinguishable, but are more similar to each other than to non-transformed or to ras transformed cells.